Isotope ratio mass spectrometry (IRMS) methods for distinguishing organic from conventional food products: A review

The use of isotopic analytical methods for food authentication was established years ago. Changes in food technology and consumer behavior, as well as the increasing number of cases of food fraud, necessitate ongoing research for reliable analytical authentication techniques. This literature review examines recent applications of stable isotope ratio analysis that can be used in cases of organic food mislabeling. Different isotope ratio mass spectrometry (IRMS) techniques are described in this article, including bulk IRMS analysis and the combination of IRMS with novel sample preparation and compound extraction techniques. Compound-specific IRMS analysis comprising mainly hyphenated techniques, such as gas chromatography GC-IRMS, was also considered, and was found to frequently overcome the limitations exhibited by bulk analysis. A wide range of food product categories were covered, including cereals, vegetables, fruit, animal products, and seafood, while the importance of statistical analysis was underlined in determining which stable isotopic compositions (δ(15N), δ(34S), δ(18O), δ(13C), or δ(2H)) could be used as reliable organic authenticity markers.